Outdated project configuration

Oct 13, 2025 by talynt.org 81 views

Introduction

When building a Flutter Android project, encountering version mismatch errors can be frustrating and time-consuming to resolve. In this article, we will discuss a specific issue where the Firebase Auth library is compiled with Kotlin 2.1.0, but the project is expecting Kotlin 1.9.0. We will explore the possible causes, solutions, and best practices to avoid such issues in the future.

Understanding the Issue

The error message typically indicates that the Firebase Auth library is compiled with a higher version of Kotlin than the project's expected version. This can happen due to various reasons, such as:

Incompatible dependencies: When using multiple libraries or plugins, it's possible that some dependencies are compiled with different versions of Kotlin, leading to version mismatch errors.
Outdated project configuration: If the project's configuration is not up-to-date, it may not be compatible with the latest versions of libraries or plugins.
Misconfigured build settings: Incorrect build settings or configurations can cause version mismatch errors.

Possible Causes

To resolve the issue, it's essential to identify the root cause. Here are some possible causes:

Firebase Auth library: The Firebase Auth library might be compiled with a higher version of Kotlin than the project's expected version.
Other dependencies: Other dependencies, such as Firebase Firestore or Firebase Realtime Database, might be compiled with different versions of Kotlin.
Project configuration: The project's configuration might be outdated or not compatible with the latest versions of libraries or plugins.

Solutions

To resolve the Kotlin version mismatch error, follow these steps:

1. Update Firebase Auth Library

Update the Firebase Auth library to the latest version that is compatible with the project's expected Kotlin version. You can do this by adding the following line to your build.gradle file:

dependencies {
    implementation 'com.google.firebase:firebase-auth:22.0.1'
}

2. Update Other Dependencies

Update other dependencies, such as Firebase Firestore or Firebase Realtime Database, to the latest versions that are compatible with the project's expected Kotlin version.

3. Update Project Configuration

Update the project's configuration to the latest version that is compatible with the project's expected Kotlin version. You can do this by running the following command:

flutter pub upgrade

4. Check Build Settings

Check the build settings and configurations to ensure that they are correct and compatible with the project's expected Kotlin version.

Best Practices

To avoid Kotlin version mismatch errors in the future, follow these best practices:

Use the latest versions of libraries and plugins: Regularly update the Firebase Auth library and other dependencies to the latest versions that are compatible with the project's expected Kotlin version.
Use a consistent version of Kotlin: Ensure that all dependencies are compiled with the same version of Kotlin as the project's expected version.
Regularly update project configuration: Regularly update the project's configuration to the latest version that is compatible with the project's expected Kotlin version.
Check build settings and configurations: Regularly check the build settings and configurations to ensure that they are correct and compatible with the project's expected Kotlin version.

Conclusion

In conclusion, Kotlin version mismatch errors can be frustrating and time-consuming to resolve. By understanding the possible causes, solutions, and best practices, you can avoid such issues in the future. Remember to update the Firebase Auth library and other dependencies to the latest versions that are compatible with the project's expected Kotlin version, update the project's configuration to the latest version that is compatible with the project's expected Kotlin version, and regularly check the build settings and configurations to ensure that they are correct and compatible with the project's expected Kotlin version.

Additional Resources

For more information on Kotlin version mismatch errors, refer to the following resources:

Firebase Auth documentation: Firebase Auth documentation
Kotlin documentation: Kotlin documentation
Flutter documentation: Flutter documentation

Kotlin Version Mismatch: Firebase Firestore Compiled with 2.1.0, Project Expecting 1.9.0
Kotlin Version Mismatch: Firebase Realtime Database Compiled with 2.1.0, Project Expecting 1.9.0
Kotlin Version Mismatch: Other Dependencies Compiled with 2.1.0, Project Expecting 1.9.0
Kotlin Version Mismatch: Firebase Auth Compiled with 2.1.0, Project Expecting 1.9.0 - Q&A ===========================================================

Introduction

In our previous article, we discussed the issue of Kotlin version mismatch errors when building a Flutter Android project. We explored the possible causes, solutions, and best practices to avoid such issues in the future. In this article, we will answer some frequently asked questions (FAQs) related to Kotlin version mismatch errors.

Q&A

Q: What is a Kotlin version mismatch error?

A: A Kotlin version mismatch error occurs when the Firebase Auth library or other dependencies are compiled with a higher version of Kotlin than the project's expected version.

Q: Why do I get a Kotlin version mismatch error?

A: You may get a Kotlin version mismatch error due to various reasons, such as:

Incompatible dependencies: When using multiple libraries or plugins, it's possible that some dependencies are compiled with different versions of Kotlin, leading to version mismatch errors.
Outdated project configuration: If the project's configuration is not up-to-date, it may not be compatible with the latest versions of libraries or plugins.
Misconfigured build settings: Incorrect build settings or configurations can cause version mismatch errors.

Q: How do I resolve a Kotlin version mismatch error?

A: To resolve a Kotlin version mismatch error, follow these steps:

Update Firebase Auth library: Update the Firebase Auth library to the latest version that is compatible with the project's expected Kotlin version.
Update other dependencies: Update other dependencies, such as Firebase Firestore or Firebase Realtime Database, to the latest versions that are compatible with the project's expected Kotlin version.
Update project configuration: Update the project's configuration to the latest version that is compatible with the project's expected Kotlin version.
Check build settings: Check the build settings and configurations to ensure that they are correct and compatible with the project's expected Kotlin version.

Q: What are the best practices to avoid Kotlin version mismatch errors?

A: To avoid Kotlin version mismatch errors, follow these best practices:

Use the latest versions of libraries and plugins: Regularly update the Firebase Auth library and other dependencies to the latest versions that are compatible with the project's expected Kotlin version.
Use a consistent version of Kotlin: Ensure that all dependencies are compiled with the same version of Kotlin as the project's expected version.
Regularly update project configuration: Regularly update the project's configuration to the latest version that is compatible with the project's expected Kotlin version.
Check build settings and configurations: Regularly check the build settings and configurations to ensure that they are correct and compatible with the project's expected Kotlin version.

Q: Can I use a different version of Kotlin for my project?

A: Yes, you can use a different version of Kotlin for your project. However, ensure that all dependencies are compiled with the same version of Kotlin as the project's expected version.

Q: How do I know which version of Kotlin is compatible with my project?

A: You can check the documentation of the Firebase Auth library and other dependencies to determine which version of Kotlin is compatible with your project.

Q: Can I use a different version of the Firebase Auth library?

A: Yes, you can use a different version of the Firebase Auth library. However, ensure that the version you choose is compatible with the project's expected Kotlin version.

Conclusion

Additional Resources

For more information on Kotlin version mismatch errors, refer to the following resources:

Firebase Auth documentation: Firebase Auth documentation
Kotlin documentation: Kotlin documentation
Flutter documentation: Flutter documentation

Kotlin Version Mismatch: Firebase Firestore Compiled with 2.1.0, Project Expecting 1.9.0
Kotlin Version Mismatch: Firebase Realtime Database Compiled with 2.1.0, Project Expecting 1.9.0
Kotlin Version Mismatch: Other Dependencies Compiled with 2.1.0, Project Expecting 1.9.0